A large variety of demonstrations are possible by using the demo
apparatus. Depending on the number of filters, prisms and other
optical elements available to you, the LED cluster can be used to
demonstrate the basic principles of colour addition,
subtraction and mixing as well as many principles of general
optics.
Colour Addition / Subtraction
During this demonstration the LED were set to show various
combinations of colours to effectively map the RGB colour gamut of
the LED cluster and illustrate the concept of colour addition. This
includes the boundary of the gamut as well as the interior, in
particular the creation of white light through RGB
combination.
The subtraction part illustrates the inverse of
colour addition by using the various colour filters over the base
plate with all clusters illuminated.
This will serve as an
introduction of wave theory of light and colour-wavelength
dependence. The emission-wavelength curves of the LED will be
presented to illustrate the concept of bandwidth. A red laser
pointer will provide an example of a very narrow bandwidth. If the
basic concepts of the wave theory of light are not part of the class
curriculum then a brief description of the wave model will be
provided as well.
Colour Dispersion
Using the base and a glass prism the basic principle of
refraction can be illustrated and in particular colour dispersion of
the light (essentially Newton’s dispersion
experiment).
Some photos of
various colour mixes made with the demo appartus can be found
here.